Methods of consolidating radioactive containing materials by hot isostatic pressing

Abstract

The present disclosure relates to a method of consolidating a calcine comprising radioactive material, the method comprising mixing 60-80% (by weight) of a radionuclide containing calcine with at least one non-radioactive additive, such as an oxide, and hot isostatic pressing the mixture to form a stable monolith of glass / ceramic. In one embodiment, the ratio of radionuclide containing calcine to additives is about 80:20 by weight, wherein the non-radioactive additive comprises oxides such as BaO, CaO, Al2O3, TiO2, SiO2 and others, that combine with the waste elements and compounds to form a ceramic mineral or glass / ceramic material, after hot isostatic pressing. Non-limiting examples of mineral phases that may be formed are: hollandite (BaAl2Ti6O16), zirconolite (CaZrThO7), and perovskite (CaTiO3).

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit of priority to U.S. Provisional Application No. 61 / 492,697, filed on Jun. 2, 2011, which is incorporated herein by reference in its entirety.FIELD OF THE DISCLOSURE[0002]The present disclosure generally relates to methods of consolidating radioactive materials by hot isostatic pressing (HIP). In particular, the present disclosure relates to a ubiquitous consolidation technique for radioactive material that is based on a novel, bottom-loading HIP method.BACKGROUND[0003]Beginning in 1953, Spent Nuclear Fuel (SNF) was reprocessed by the Department of Energy to recover highly enriched uranium and other nuclear related products. Processing operations involved multiple cycles of solvent extraction to recover uranium-235 and other defense-related materials from SNF. The end of the Cold War also ended the program to reprocess SNF, with the last reprocessing cycle ending in 1994. These reprocessing activities, as...

AI Technical Summary

Benefits of technology

The invention allows for faster processing by heating and loading sealed cans through the bottom of a vessel using a fully automated system. This can reduce the process time by up to ⅔. The cans can be heated and loaded at temperatures up to 600°C.

Problems solved by technology

Constraints imposed by the consolidation technology on the waste form chemistry will result in a reduction in waste loading efficiency and process flexibility.

Therefore, the glass cannot be designed solely to suit the waste stream.

These constraints significantly reduce the maximum achievable waste loading efficiency and / or process flexibility and therefore substantially increase the number of waste canisters required.

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